Craftsman 3One 917.257560 Owner's Manual page 24

E CE AN ADJ ENTS
TO ADJUST CARBURETOR
(See Figs.
32 and
33)
The carburetor has been preset at the factory and adjust-
ment should not be necessary. However, minor adjust-
ment may be required to compensate for differences in fuel,
temperature, altitude or load. If the carburetor does need
adjustment, proceed as follows:
]n general, turning the mixture screw in (clockwise) de-
creases the supply of fuel to the engine giving a leaner fuel/
air mixture Turning the mixture screw out (counterctocko
wise) increases the supply of fuel to the engine giving a
richer fuel/air mixture.
IMPORTANT: DAMAGE TO THE NEEDLES AND THE
SEATS tN CARBURETOR MAY RESULT IF SCREW IS
TURNED tN TOO TIGHT.
PREUMINARY SE_ING o
Be sure you have a clean air filter, and the throttle
contro_ cable and choke are adjusted properly (see
above).
o With engine off turn idle mixture screw in (clockwise)
closing it finger tight and then turn out (counterclock-
wise) 1-t/4 to 1-1/2 turns.
FINAL SETTING o
• Start engine and aiiow to warm for five minutes. Make
final adjustments with engine running and shift/motion
control lever in neutral (N) position.
o With throttle control lever in slow (_) position, hold
throttle lever against idle speed screw and adjust idle
speed screw to obtain 1200 to !400 RPM
• While stir holding throttle lever against idle speed
screw, turn idle mixture screw in (clockwise) until
engine begins to die and then turn out (counterclock-
wise) untit engine runs rough. Turn screw to a point
midway between those two positions.
o Continue to hold throttle lever against idle speed screw
and adjust idle speed screw to obtain 900 to 1200 RPM.
Release throttle lever.
ACCELERATION TEST-
Move throttle control lever from slow (_) to fast (,1_)
position. If engine hesitates or dies, turn idle mixture
screw out (counterclockwise) 1/8 turn° Repeat test
and continue to adjust, if necessary, until engine accel-
erates smootNyo
High speed stop is factory' adjusted. Do not adjust -
damage may result.
iMPORTANT: NEVER TAMPER WITH THE ENGINE
GOVERNOR, WHICH IS FACTORY SET FOR PROPER
ENGINE SPEED. OVERSPEEDING THE ENGINE ABOVE
THE FACTORY HiGH SPEED SETTING CAN BE
DANGEROUS. IFYOU THJNKTHE ENGINEoGOVERNED
HIGH SPEED NEEDS ADJUSTING, CONTACT YOUR
NEAREST AUTHORIZED SERVlCE CENTER/
DEPARTMENT, WHICH HAS PROPER EQUIPMENT AND
EXPERIENCE TO MAKE ANY NECESSARY
ADJUSTMENTS,
IDLE SPEED
SCREW
THROTTLE
LEVER
RG. 32
THROTTLE
LEVER
FJGo33
24